Paper-board.



c. s. BIRD & .e. R.- WYMAN.

PAPER BOARD. APPLIOATIOH FILED JULY-5, 1912.

Patented Oct. 7, 1913.

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CHARLES S. BIRD AND GEORGE R. VVYMAN, 0F WALPOLE, MASSACHUSETTS; SAID" WYMAN ASSIGNOR TO SAID BIRD.

rerun-BOAR Specification of Letters Patent.

Patented (let. F, 31913.

Application filed July 5, 1912. Serial No. 707,835.

To all whom it may concern:

Be it known that we, CHARLES S.-Bmn' county of Norfolk andv State of Massachw have-invented certain new and useful Paper Board, of which the following is a specification.

Our present invention pertains to an improved paper-board the construction :and advantages of which will. be hereinafter set.

Improvements in forth.

Paper-board has of recent years come into somewhat extended use and its field of ap-; plication is Widening, this primarily by reason of the fact that lumber is becoming more and more expensive, and for the further reason that the manufacturers of such board are producing a better article than formerly. There is present, however, in the usual commercial paper-board of today one inherent defect which renders it unsatisfactory for many purposes, namely, the tendency to Warp and buckle priorto or after it is positioned.

The main object of the present invention is to produce a board which will maintain its evenness and present a smooth surface or face, particularly so after it is fastened in place. This is accomplished primarily by charging the board, during its process of manufacture, with an appreciable amount of moisture, which moisture is, after being applied, slowly given off during a considerable period of time. Thus, when the board, with a certain percentage of contained moisture, is secured in place, around its edges by tacking it, which is the usual manner of fastening the same, it becomes taut and maintains such position or condition indefinitely.

A piece of board manufactured in accordance with our invention is sought to be shown in the annexed drawing, wherein it appears in perspective, with the various plies separatedat one corner to show that the structure is a laminated one.

In carrying out the process of manufacture, we take a number of plies of paper, as 1 and apply a suitable adhesive thereto, except, of course, the outer faces of the outer plies, and bring the same together under pressure through the agency of any suitable means. The adhesive whicli is employed, such as glue, silicate of soda, or the iike, will have present a greater amount of moisture than is necessary to ordinarily effect a cementation of the layers. Such excess of moisture (from 5- to-10 per cent-., by weight), is taken up by the paper-stock andis retained. therein, for when the board passes from thepressure rolls, which are used in the formation thereof it is "treated upon its outer faces with a suitable waterrepellent substance, such as paraffin wax, gum, or. any quick-drying agent, either heated or. dissolved in a volatile solvent. If desired, oneor .both facesmay be. passed beneath an engraved roll, to print thereon any desired design, such, for instance, as an imitation wood-grain as shown upon the outer ply 2, such printing, of course, being effected prior to the application of the Waterproofing material. Such surface ornamentation may be applied tothe outer plies prior to the formation of the board and,- furthermore, such plies may be of a-b'ettei grade of stock than the others, in order to produce a better finish.

Instead of applying to or charging the stock with the excess moisturethrough the medium of the adhesive, the plies may be damped by passing the same over a roll, covered or plain, to which water, is sup; plied in any suitable manner. It is even conceivable that the plies might be sprayed,

though the application of the moisture" through the adhesive as a carrying medium is preferred, and is found to produce an article having the characteristics desired.

' Board manufactured as above outlined,- gives highly satisfactory results, and does not warp or buckle. It is assumed that as the fibers are slightly distended or swollen as the board is "produced they naturally shrink or shorten up in time and consequently, tend to cause the positioned, sheet, usually fastened around the edges, to become taut. Furthermore, there is little or no tendency for the board to absorb moisture, for the reason that it is already-impregnated with an amount of moisture greater than that normally contained in the atmosphere, and for the further reason that r It has been found from experience that board thus made will stand shipment and storage for a considerable period of time,

and yet not lose sufiicient moisture to prevent it from tightening up or becoming taut when finally secured in place.

Where the board is used as a finishing strip, that is, in a narrow piece which is adapted to overlie the adjacent edges of two sheets, as in panel-work, the edges of the strip are somewhat condensed and burnished down by the cutters and such edges are waterproofed along with the faces of the strip.

No claim is made to the process herein set forth, that being reserved for. a divisional application.

Having thus described our invention, what we claim is:

1. As a new article of manufacture, a com- 7 cured to one another by a suitableadhesive and charged within the fibers thereof with an amount of moisture approximating ten per cent. byweight, teriorly waterproofed.

- 2. As a new article of manufacture, a composite and substantially rigid board comprising a plurality of plies of paper secured to one another by a suitable adhesive, and charged with an excess of moisture over that required for adhesion, the outer surface of the sheet being waterproofed and presenting a substantially smooth and unbroken surface.

In testimony whereof we have signed our names to this specification in the presence of two subscribing witnesses.

CHARLES S. BIRD. GEORGE R. WYMAN. Witnesses:

M. M. Burns, W. M. PAINE.

the board being ex- 

